Following the launch of Internet Explorer 9, Google has released a preview WebM plug-in for IE9 on Windows Vista and Windows 7. The filter also allows WebM-encoded video playback on Windows Media Player and Windows Media Center. Installing it doesn't make any visible changes beyond making WebM video playback work.
The download page originally had the following tongue-in-cheek message from Google, but has since been removed: "They said elephants couldn't ride flying dolphins. They said that one of the world’s most popular browsers couldn't play WebM video in HTML5. They were wrong."
Two months ago, Google announced that it would be dropping support for H.264 in Chrome and only support WebM going forward. Days later, the search giant promised to offer WebM plug-ins for Microsoft's Internet Explorer 9 and Apple's Safari.
Three months ago, Microsoft announced an updated version of its Windows Media Player plug-in for Mozilla Firefox that enabled H.264-encoded video on HTML5 by using built-in capabilities available on Windows 7. Last month, it also the plug-inoffered a plug-in for Google Chrome.
The HTML5 video tag battle is getting ugly. Microsoft and Apple are betting on H.264 since it is much more widely adopted and because it has hardware decoders, which allows mobile devices to get long battery life and smooth performance for video playback. Google developed WebM as an alternative, and it has managed to get Mozilla and Opera on board because the platform is more open and is free. Microsoft has said that Internet Explorer 9 would only support H.264, but that it would make an exception for WebM, as long as the user installs the corresponding codec. Apple has so far stayed silent and is sticking solely with H.264.
All the browser vendors agree that their software should have support for the HTML5 video tag, but they can't agree on the standard that will allow it. Microsoft's and Google's plug-ins are nice, but they aren't helpful in making any progress towards unification.